1. Field of the Invention
This invention relates to wheel nuts having caps that surround the end of the nut from which a wheel stud end may project, and more particularly to such a wheel nut wherein the wrench flat's surface is formed partially by the uncovered nut body and partially by the sheath body.
2. Prior Art
Nuts having sheet metal or plastic caps enclosing the volume from which the shank of a bolt projects are commonly used to retain a wheel to the projecting studs of an axle hub. The capped volume protects the projecting end of the stud from moisture which might cause it to rust and from impacts which might damage the thread and make it difficult to remove the nut. These caps are sometimes formed of stainless steel or a decorative plastic for aesthetic reasons.
U.S. Pat. No. 3,364,806 discloses such a capped wheel nut wherein the nut end which contacts the wheel is formed with a pair of conical surfaces joined by a short cylindrical land. The sides of the nut are covered with a sheet metal sheath forming a domed cap at one end of the nut and terminates at the land between the two conical surfaces at the opposite end. The edge of the sheath makes smooth contact with the cylindrical land and the conical surface at the extreme end of the nut abuts the conical depression in the wheel surrounding a stud hole. This arrangement terminates the sheath so that the sheath does not contact the wheel, and accordingly is not loosened by forces imposed between the nut and the wheel during wrenching. However, it is relatively expensive to manufacture because of the forming operations required on the nut end and the difficulty of uniformly forming the edge of the sheath.
The present invention is broadly directed toward a capped wheel nut having all of the advantages of the nut disclosed in my previous patent, noted above, which is less expensive to manufacture.